血管性痴呆患者MTHFR基因多态性和血浆Hcy水平检测*
Detection of MTHFR gene polymorphism and plasma homocysteine levels in patients with vascular dementia

目的:探讨血管性痴呆(VaD)与MTHFR基因多态性和血浆同型半胱氨酸(Hcy)水平的关系。方法:选取73例VaD患者和75例非痴呆脑梗死患者,使用简易精神状态检查量表(MMSE)评定VaD患者痴呆严重程度。应用PCR-芯片杂交法测定其MTHFR基因多态性,酶循环法测定血浆Hcy水平,免疫分析法测定叶酸、维生素B12水平。结果:VaD组MTHFR基因TT基因型及T等位基因频率高于非痴呆脑梗死组(P＜0.05),MTHFR基因TT、CT型血浆Hcy水平高于CC型(P＜0.001); VaD组血浆Hcy水平显著高于非痴呆脑梗死组(P＜0.001),痴呆程度与血浆Hcy水平呈正相关(r=0.227,P=0.018); 非痴呆脑梗死组叶酸、维生素B12水平高于VaD组(P＜0.05)。结论:MTHFR基因C677T位点突变及高Hcy血症可能和VaD的发生相关。
Aim: To investigate the association between MTHFR gene polymorphism and plasma homocysteine(Hcy)levels in patients with vascular dementia(VaD).Methods: A total of 73 patients with VaD and 75 patients with nondemented cerebral infarction were recruited in the study. PCR-RFLP was used to analyze the polymorphism of MTHFR gene. The folic acid and vitamin B12 levels were measured using immunoassay method. And circulating enzymatic method was empolyed to test the Hcy concentration in plasma. The degree of dementia was classified according to the MMSE for patients with VaD.Results: The genotype TT and T allele frequency of MTHFR gene in VaD group were significantly higher than that in nondementia cerebral infarction group(P＜0.05). The concentration of plasma Hcy was higher in patients with TT and CT type than those with CC genotype(P＜0.001). Mean total plasma Hcy concentration was significantly higher in VaD patients than that in the patients with nondemented cerebral infarction(P＜0.001), but the levels of folate and vitamin B12 were significantly lower in VaD patients than in the patients with nondemented cerebral infarction(P＜0.05). The degree of dementia was positively related with plasma Hcy level(r=0.227,P=0.018).Conclusion: Genetic mutations of MTHFR C677T and the hyperhomocysteinemia may closely related to the occurrence of VaD